Stock-Based Compensation (Tables)

12 Months Ended

Mar. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units

The following tables summarize the allocation of the stock-based compensation expense (in thousands):

	Fiscal Years Ended March 31,
	2016			2015		2014
Stock-based compensation expense by type of grant:
Stock options and employee stock purchase rights	$	1,155		$	1,408	$	2,520
RSUs	24,667			16,892		14,517
	25,822			18,300		17,037
Stock-based compensation expensed from (capitalized to) inventory	(18		)	5		(16		)
Total stock-based compensation expense	$	25,804		$	18,305	$	17,021

Summary of Stock-Based Compensation Expense

	Fiscal Years Ended March 31,
	2016			2015		2014
Stock-based compensation expense by cost centers:
Cost of revenues	$	540		$	285	$	460
Research and development	18,018			11,657		6,371
Selling, general and administrative	7,264			6,358		10,206
	25,822			18,300		17,037
Stock-based compensation expensed from (capitalized to) inventory	(18		)	5		(16		)
Total stock-based compensation expense	$	25,804		$	18,305	$	17,021

Schedule of Weighted-Average Assumptions Used to Estimate the Fair Value of Stock Options

The fair values of the options and employee stock purchase rights granted are estimated as of the grant date using the Black-Scholes option-pricing model with the following assumptions:

	Options					Employee Stock Purchase Rights
	Fiscal Years Ended March 31,					Fiscal Years Ended March 31,
	2016	2015	2014			2016			2015			2014
Expected life (years)	*	*	4.4			0.5			0.5			0.5
Risk-free interest rate	*	*	0.6		%	0.1		%	0.1		%	—		%
Volatility	*	*	49		%	57		%	57		%	56		%
Expected forfeiture rate	*	*	5.8		%	—		%	—		%	—		%
Weighted average fair value	*	*	$	2.95		$	1.80		$	2.17		$	3.40

* The Company did not grant options during the twelve months ended March 31, 2016 and 2015.